A257245 - OEIS

%I #12 Apr 19 2015 22:24:53

%S 2,3,3,3,3,5,5,3,3,5,7,7,7,3,19,7,5,5,7,5,19,11,13,13,23,13,11,11,61,

%T 31,13,19,43,13,7,5,61,31,23,127,7,151,19,181,13,43,31,233,13,13,7,11,

%U 19,31,59,31,31,163,41,41,113,11,19,19,409,41,41,41,19,41,113,29,167,13,17,11,179,19,19,13,5

%N Odd bisection of A257244: a(n) = A257244(2n - 1).

%H Antti Karttunen, <a href="/A257245/b257245.txt">Table of n, a(n) for n = 1..2048</a>

%F a(n) = A257244(2n - 1).

%F a(n) = A006530(A256393(2n - 1)). [Equally, the largest prime factor of A256393(2n-1).]

%F Other identities and observations:

%F For all n >= 1, a(n) >= A257246(n).

%o (Scheme, alternative definitions)

%o (define (A257245 n) (A257244 (+ n n -1)))

%o (define (A257245 n) (A006530 (A256393 (+ n n -1))))

%Y Cf. A006530, A256393, A257244.

%Y Cf. also A257246 (the other bisection), A257247 (gives the positions where both bisections have the same value).

%K nonn

%O 1,1

%A _Antti Karttunen_, Apr 19 2015